1. Technical Field
The present invention relates to a wiring mounting structure that includes a connection wiring and a method of manufacturing the wiring mounting structure, and a liquid ejecting head and a liquid ejecting apparatus.
2. Related Art
A liquid ejecting head that ejects a droplet includes a flow path formation substrate (second base) in which a pressure generating chamber communicates with a nozzle opening is formed, a piezoelectric actuator provided on one surface side of the flow path formation substrate, and a protection substrate (first base) that is joined to the flow path formation substrate on a side of the piezoelectric actuator. The liquid ejecting head causes the piezoelectric actuator to produce a pressure change in a liquid in the pressure generating chamber and thereby ejects the liquid from a nozzle opening.
In such an ink jet-type recording head, a configuration has been proposed, in which a drive circuit (semiconductor element) is provided on a surface opposite to a surface of the protection substrate to which the flow path formation substrate is joined, an opening is formed on the protection substrate, a wiring connected to the piezoelectric actuator in the opening is exposed, and the drive circuit and the piezoelectric actuator are connected electrically to each other through the connection wiring provided on a side wall of the opening of the protection substrate (for example, see JP-A-2007-290232).
In such an ink jet-type recording head, the flow path formation substrate and the protection substrate are joined to each other by an adhesive, then the connection wiring is formed to be disposed on the side wall of the opening, a front surface of the adhesive and a front surface of the flow path formation substrate by film deposition, and then patterning is performed on the connection wiring into a predetermined shape by a lithography process or the like.
In addition, there has been proposed a configuration in which an insulation member that covers the side wall and the front surface of the flow path formation substrate is provided such that the connection wiring is formed on the insulation member (for example, see JP-A-2007-66965).
However, in the case where the flow path formation substrate and the protection substrate are joined to each other and then the connection wiring is formed by the film deposition and the lithography process, a problem arises in that resists for patterning the connection wiring on a corner that is formed between the side wall and the front surface of the flow path formation substrate are accumulated, thus it is not possible to form the resists to have the same thickness, and overexposure is needed, which causes the patterned connection wiring to have a non-uniform width.
In addition, as in JP-A-2007-66965, in the case where the insulation member is provided to cover the corner formed by the side wall and the front surface of the flow path formation substrate, a problem arises in that a process of providing the insulation member is needed and thus a manufacturing operation becomes complicated and cost of manufacturing is increased.
Such problems arise in a wiring mounting structure that is used not only in the liquid ejecting head, but also in another device.